Catch for a packing case or the like



Dec. 25, 1962 G." E. SWANSON I CATCH FOR A PACKING CASE OR THE LIKE 2Sheets-Sheet 1 Original Filed July 31, 1958 FIG.7 'Flc-m F|G.9 FIG.1O

F'IG.5 II-lens A TTORNEYS 2 Sheets-Sheet 2 G. E. SWANSON CATCH FOR APACKING CASE OR THE LIKE N w w w i RN E mm va m ,(W m m 0 vs f ,w WM A m8 M 30, w w w B 9 w m. ami 522: a G a w .wfik MW 6 52:: y M 8 0. M a, 44 p r 7 l H 22 3 ,4 2 Hui s \a. 1 4 a 8 5 a z 8 F i I W. J 7 aw m 4 v a8 W Z 6F w F Q J4. fr I III 6 ."I'IIEIFHV 4 L7immg====== A. W o EVILDec. 25, 1962 Original Filed July 31, 1958 ilnited States 3,070,396Patented Dec. 25, 1962 Fine 3,070,396 CATCH FOR A PACKING CASE OR THELHQE Gunnar E. Swanson, Middletown, Conan, assignor to The NielsenHardware Corporation, Hartford, Conn, a corporation of ConnecticutOriginal application July 31, 1958, Ser. No. 752,302, new Patent No.2,951,722, dated Sept. 6, 1%11. Divided and this application Oct. 26,195%, Ser. No. 848,587

10 Claims. (Cl. 292-447) This application is a division of my copendingapplication Serial No. 752,302, filed July 31, 1958, entitled Catch fora Packing Case or the Like, new Patent No. 2,951,722, dated September 6,1960.

The invention relates to a catch for use on a packing case or the likehaving a main body and having a cover upwardly separable from said mainbody. A strike is provided which is adapted to be fixedly attached tosaid case cover, and a catch unit is provided which is adapted to befixedly attached to said case body below the strike. The catch unit isof the type comprising a lever movable about a fixed axis and a yokepivoted to said lever at a movable axis and engageable with the strike.The relationship of parts is such that said yoke when so engaged andsaid lever when in said forward position constitute toggle links movablerespectively about the pivotal connection with the strike and about saidfixed lever axis so that said movable yoke axis has an overcenter actionwith respect to said fixed lever axis upon movement of the lever to arearward position.

One object of the invention is to provide an improved adjusting meansbetween the fixed lever axis and the movable yoke axis which makes itpossible for the case cover to be always pressed firmly downwardlyagainst the case body notwithstanding minor inaccuracies in the locationof the strike and of the catch unit on the case cover and on the casebody.

A further object of the invention is to provide an adjusting means asset forth in the last preceding paragraph which includes a spring forresisting upward movement of the yoke axis and also an adjustable screwfor positively limiting upward movement of the yoke axis in oppositionto the resistance of the spring.

Other objects of the invention will be apparent from the followingdescription and the claims.

The drawings show two embodiments of the invention and such embodimentswill be described, but it will be understood that various changes may bemade from the constructions disclosed, and that the drawings anddescription are not to be construed as defining or limiting the scope ofthe invention, the claims forming a part of this specification beingrelied upon for that purpose.

' Of the drawings:

FIG. 1 is a side view of a catch embodying the invention, said catchbeing shown in its position of initial engagement.

FIG. 2 is a side view similar to FIG. 1, but showing the catch in anintermediate position, a fragmentary portion at the bottom being shownin vertical central section.

FIG. 3 is a side view similar to FIG. 2, but showing the catch in itsposition of full engagement.

FIG. 4 is a front view of the catch as shown in FIG. 3.

- FIG. 5 is a front view of the base separate from other parts.

FIG. 6 is a side view of the base as shown in FIG. 5.

FIG. 7 is a front view of the main lever separate from other parts.

FIG. 8 is a side view of the lever as shown in FIG. 7.

FIG. 9 is a front view of the yoke separate from other parts.

FIG. 10 is a side view of the yoke as shown inFIG. 9.

FIG. 11 is an enlarged vertical sectional view taken along the line 1111of FIG. 4.

FIG. 12 is a sectional view similar to FIG. 11, but showing the catch ina position preparatory to release.

' FIG. 13 is a sectional view similar to FIG. 12, but showing the catchin position for disengagement.

FIG. 14 is a horizontal sectional view taken along the line 14-14 ofFIGS. 3 and 11.

FIG. 15 is a horizontal sectional view taken along the lines 15-15 ofFIGS. 3 and 11.

FIG. 16 is a horizontal sectional view taken along the lines 16-16 ofFIGS. 3 and 11.

FIG. 17 is a front view generally similar to FIG. 4, but showing analternative embodiment of the invention.

FIG. 18 is a vertical sectional view taken along the line 18-18 of FIG.17.

FIG. 19 is a vertical sectional view taken along the line 19-19 of FIG.18.

A catch embodying the invention is adapted for use on a packing case orthe like having a main body A and having a cover B upwardly separablefrom said main body. The catch includes a strike 10 adapted to befixedly attached to said case cover B, said strike having a relative- 1yfixed book 12. The catch also includes a catch unit which has a base 14adapted to be fixedly attached to said case body A below said strike 10.A main lever 16 is connected with the base 14 for movement about ahorizontal transverse axis which is fixed against forward and rearwardmovement relatively to the bases, such an axis being provided by a firstpivot pin 18. A yoke 20 is pivoted to said lever 16 for movement about amovable horizontal transverse axis at a second pivot pin 22 spaced fromsaid lever axis 18. The yoke 20 is pivotally engageable at its upper endwith the book 12 of said strike 10 when said lever 16 is in a forwardposition as shown in FIG. 1. Said yoke 20 when pivotally engaged withthe book of said strike and said lever 16 when in said forward positionconstitute toggle links movable respectively about the pivotalconnection of the yoke with the strike 10 and about said lever axis at18 so that said movable yoke axis at 22 has an overcenter action withrespect to said lever axis at 18 upon movement of the yoke 20 and thelever 16 to rearward cover holding position as shown in FIG. 3.

The base 14- is shown as having two parallel forwardly projecting wings24, 24 having holes 18*, 18 therein for the first pivot pin 13. Thelever 16 is shown as having two rearwardly projecting wings 26, 26located between the base wings 2.4, 24 and having holes 18 18 for saidpivot pin 18 and preferably also having holes 28*, 28 for another pin 28to be described. In addition the wings 24, 24 have holes 22*, 22 for thesecond pivot pin 22. The last said holes 22 22 are vertically elongatedto permit vertical adjustment of said pin 22. The yoke an is shown ashaving two rearwardly projecting wings 319, 30 having holes 22 22" forthe pivot pin 22.

I The base 14 has forwardly projecting teeth 32, 32 and the wings 26, 26of the lever 16 have notches 34, 34 into which the teeth fit when thecatch is in fully engaged position as shown in FIG. 3. The teeth and thenotches are adapted to carry a portion of the vertical stress and tothus avoid undue stress on the pins 18 and 28.

In accordance with the invention, a manually rotatable adjusting screwis provided on the lever 16 for enabling said yoke axis at 22 to bemoved vertically to vary the distance between said base and said strikewhen said yoke and said lever are in their said cover holding posi-'tions as shown in FIGS. 3 and 11. It is thus possible to make correctionfor minor inaccuracies in the location of the base 14 and of the strike10 respectively on the body A and on the cover B. Within reasonablelimits, the. stated adjustment makes it possible, notwithstanding such 3inaccuracies, for the cover to be always firmly pressed downwardlyagainst the body when the yoke and lever are moved to their coverholding positions. I p

A member having a vertical aperture therein is carried by the lever 16in fixed relationship with the axisof the first pin. This member ispreferably a structurally sepa-' rate block such as the block 36 shownin FIGS. 11 to 13. The block such as 36 has a vertical aperture thereinand a vertical screw such as 40 extends through the vertical apertureand is adapted upon rotary adjustment thereof to vary the distancebetween the axis of the first and second pins. The screw has means atthe top thereof and closely adjacent the first pin for effecting saidrotary adjustment, this means being shown as a screw driver slot in thescrew. The screw is readily accessible at the top so that adjustment canbe made notwithstanding the disclosed catch device at the bottom of thelever.

Referring particularly to the catch shown in FIGS. 1 to 16, the block 36is interposed between the wings 26, 26 of the lever 16, this block beingtransversely apertured to receive and fit the first pivot pin 18. Alsointerposed between said lever wings 26, 26- and below the block 36 is asecond block 38 apertured to receive and fit the pivot pin 22, saidsecond block being vertically movable relatively to said lever 16. Theupper portion of the screw 46 extends through said vertical hole in theblock 36 and the screw is held to prevent relative vertical movement.The lower portion of the screw 49 is entered in a vertical threaded holein the block 38. For preventing vertical movement, the screw 40 has anannular groove through which the pivot pin 18 extends, said pin at leastassisting in preventing bodily vertical movement of'said' screw.Preferably another transverse pin 23 extends through an aperture in theblock 36 and into the annular groove in the screw, this last said pincooperating with the pivot pin 18 to prevent vertical movement of thescrew. By means of said slot in its upper end, the screw 40 may beturned to vertically adjust the block 38 and pivot pin 22 relatively tothe pivot pin 18. The vertical adjustment of the pin 22 relatively tothe lever 16 is permitted by the vertical elongation of the holes 22*,22 The yoke is vertically adjusted with the pin 22 and the yoke axis istherefore moved or adjusted with respect to the lever axis at 18.

A manually movable releasable latch device is preferably provided whichnormally engages the base 14 and the lever 16 for preventing movement ofsaid lever forwardly from its rear position. Preferably said latchdevice comprises an abutment in fixed position on the base and alsocomprises a latch carried by the movable lever and normally inengagement with the abutment to retain the lever in rearward position,said latch being manually movable relatively to the lever and out ofengagement with said abutment.

As shown the base 14 has two forwardly projecting wings 42, 42 near itsbottom and a transverse pin 44 is secured to said wings. The pin 41-constitutes the beforementioned abutment on the base, this abutmenthaving a rearwardly exposed face. The relatively movable latch on thelever is shown at 46, this latch being spring pressed downwardly andmanually movable upwardly. The latch preferably comprises twotransversely spaced active portions and said active portions haveinclined cam faces 48 which enable the latch to automatically moveupwardly, as shown in FIG. 2, when the lever 16 is moved rearwardly fromthe position shown in FIG. 1 to the position shown in FIGS. 3 and 11. Atthe last said position the latch 46 snaps downwardly behind the abutment44.

For manually moving the latch 46 upwardly there is provided a fingerpiece 50 which is carried by the lever 16 and which is spaced forwardlyfrom the base 14 to provide finger space behind it. Said finger piecehas rearwardly projecting wings 52, 52 at the sides thereof, said wings52, 52 being at the outer sides of the wings 26, 26 on the lever 16.Said lever wings 26, 26 have slots 54 which are vertical and slots 56which are inclined upwardly and rearwardly. Transverse pins 58 and 60extend through and fit holes in the wings 52, 52 of the finger piece andalso through said slots 54 and 56 in the wings 26, 26 of the lever. Thepins 58 and 60 are at the lower ends of the slots 54 and 56 and thefinger piece therefore cannot move downwardly beyond the position shownin FIG. 3. When the latch 46 is in its engaged position as shown in FIG.11, the front wall of the finger piece 50 registers with the front wallof the lever 46. Said finger piece has an offset upward extension 62which fits behind and engages the rear face of said front wall of thelever 16. The extension 62 has an upwardly and rearwardly inclined frontface and this cooperates with the adjacent front portion of the lever 16to prevent vertical movement of the finger piece.

The latch 46 is U-shaped in horizontal plan, as shown in FIG. 16, saidlatch having wings 64, 64. The latch is located between the wings 26, 26of the lever and the active portions of said latch are at the lower endsof said latch wings 64, 64. Said wings of the latch have vertical slots66 through which the pin 58 extends and said wings have upwardly andrearwardly inclined slots 68 through which the pin extends. A transversenormally vertical plate 76 is secured tothe wings 26, 26 of the levernear the rear thereof and behind the latch 46. A compression coil spring72 is interposed between the plate and the front wall of the latch 46.The spring fits a tab bent forwardly from the plate 76 and a tab bentrearwardly from the front wall of the latch. Said spring 72 biases thelatch 46 to its engaged position as.

shown in FIGS. 3 and 11. Downward movement of the latch relatively tothe finger piece 50 is limited by the engagement of the upper ends ofthe slots 66 and 68 with the pins 58 and 60. When the upper ends of saidslots 66 and 68 engage the pins 58 and 60, the spring 72 also biases thefinger piece 50 downwardly. Downward movement of the finger piece islimited by the engagement of the pins 58 and 60 with the lower ends ofthe slots 54 and 56 in the wings 26, 26 of the lever.

When the catch is moved from the FIG. 1 position to the FIG. 3 position,the latch 46 engages the abutment 44 as shown in FIG. 2 and is cammedupwardly. The latch moves upwardly in opposition to the spring 72 and:independently of the. finger piece 50. In the FIG. 3 position the spring72 has moved the latch so that its active) portions are behind. theabutment 44 to prevent forward movement of the lever.

When the catch is to be. disengaged, the inclined face on the extension62 of the finger piece and the inclination of the slots 56 in the leverwings cooperate to prevent the finger piece 50 from moving verticallyupwardly. Said inclined face and slots cause the finger piece:

to have combined upward and rearward swinging movement about the pin 58when. substantially forward pres.- sure is applied manually to the lowerend of said finger piece. When such pressure is applied, the fingerpiece is moved from the FIG. 11 position to the FIG. 12 position and itcarries the latch 46 with it, the latch being.

thus moved out of its engaging relationship with the abutment 44. Assoon as the FIG. 12 position has been reached, the forward pressure onthe lower end of the finger piece is continued, and motion is continuedto the FIG. 13 position which is such that the yoke 20 can be disengagedfrom the strike 10. It will be seen that substantially forward manualpressure applied to the lower end of the finger piece 50 serves not onlyto move the latch 46 upwardly for releasing the lever 16 but also tomove said lever forwardly.

It will be observed, particularly from FIG. 11, that the combined centerof gravity of the latch 46 and of the finger piece 50 is above the axisof the pin 58. Therefore any shock that would tend to move the lever 16forwardly and which would thus tend to release the catch, would alsotend to move the latch and finger piece forwardly and downwardly so thatthey remain in the positions shown in FIG. 11. With the parts in theFIG. 11 position, the lever 16 is iocked against forward movement.

FIGS. 17 to 19 show an alternative catch unit, generally similar to theupper portion of the catch unit shown in FIGS. 1 to 16, but omitting themeans for releasably holding the parts in cover retaining positions.

The unit shown in FIGS. 17 to 19 has a base 74 similar to the base 14. Amain lever 76 is connected with the base for movement about a horizontaltransverse pivotal axis, said axis being fixed against forward andrearward movement relatively to the base. As shown, the base hasforwardly extending wings 80, 80 and the lever 76 carries a block 82which is vertically movable relatively to the main body of the lever andwhich has integral pintles 78, 78 entering pivot holes in said wings 80,89. The pintles 78, 78 constitute a pivot pin corresponding generally tothe first pivot pin 18 shown in FIGS. 11 to 13, and said pintles providethe before-mentioned transverse pivotal axis.

A yoke 84, generally similar to the yoke 20, is connected with the lever'76 for pivotal movement about a transverse axis that is movable towardand from the lever axis at 78. When the parts are in their normalpositions, as shown, the yoke axis is movable vertically. Preferably andas shown, the yoke is pivotally connect- 'ed to the lever by means of atransverse pivot pin 86 extending through holes in rearwardly extendingwings 88, 88 on the lever. The pivotal axis of the yoke is verticallymovable as stated, and the entire lever is vertically movable with theyoke axis. The lever wings 88, 88 have vertically elongated slots 90, 90therein, and the pintles 78, 78 on the block 82 extend through theseholes. The elongated slots 90, 9t} permit the stated vertical movementof the lever and of the yoke axis.

At least one vertical compression spring is preferably provided forresisting upward movement of the movable yoke axis toward said fixedlever axis. As shown, there are two vertical compression springs 92, 92each abutting at its lower end against an abutment in fixed relation tothe yoke axis at the pin 86 and each having its upper end held in fixedrelation to the fixed lever axis 78. When a block 82 is provided thesprings abut against said block. The said abutment for the lower ends ofthe springs may be a plate 94 above the pin 86 and in engagementtherewith. The springs 92, 92 tend to hold the pintles 78, 78 at theupper ends of the slots 90, 90, and said springs will yield to permitupward movement of the abutment 94 and the pin 86 when the yoke isengaged with the strike and when the parts are moved to their coverretaining positions. The springs 92, 92 may serve within the limits ofthe pressure applied thereby to al- ,ways press the cover firmlydownwardly against the case {bodynotwithstandingminor inaccuracies inthe location of the strike and of the catch unit on the case cover andon the case body.

The pressure applied by the springs 92, 92 may ordinarily be sufiicient,but in order to provide a heavier and more positive pressure one or moreadjustable screws are provided for limiting upward movement of themovable yoke axis at the pin 86 toward the lever 78 axis. When a blocksuch as 82 is provided, the screw or screws are carried by said block.Preferably and as shown, threaded holes are provided in the block 82 andthe screws 96, 96 are entered in these holes. Preferably, the screwsextend through the springs 92, 92 and the lower ends of the screws areclosely adjacent the abutment plate 94. As shown, the screws 96, 96 donot engage the abutment plate 94, and said plate and the pin 36 may moveupwardly in opposition to the springs and to the extent permitted by thescrews. The screws may be adjusted to vary the extent of permittedupward movement. Furthermore, the screws may be adjusted to 6 firmlyengage the plate 94 and'to thus positively prevent any upward movementof the pin 86. Within reasonable limits, adjustment of said screws 96,96 makes it possible for the cover to be always firmly presseddownwardly against the body when the catch is in its fully engagedposition as shown in FIGS. 17 to 19.

In the use catch, the springs 92, 92 apply initial pressure to the coveras the parts are moved to their normal positions as shown, and in manyinstances this spring pressure is sufiicient and the screws 96, 96 areineffective. But when greater pressure is necessary, the screws areadjusted to engage the abutment immediately before the completion of thetoggle action so as to apply positive pressure to the cover as thetoggle action is completed.

The invention claimed is:

1. In a catch for use on a packing case or the like having a main bodyand having a cover upwardly separable from' said main body, thecombination of a strike adapted to be fixedly attached to said casecover and having a relatively fixed hook, a base adapted to be fixedlyattached to said case body below said strike, a horizontal transversepivot pin in fixed relationship with the base, a main lever engagingsaid pin and thereby connected with said base for pivotal movement aboutthe axis of the pin, a second horizontal transverse pivot pin carried bythe main lever and spaced from said first pin, a yoke engaging thesecond pin and thereby connected with the lever for pivotal movementabout the axis of the second pin which yoke has a portion pivotallyengageable at its upper end with the hook of the strike when said leveris in a forward position, said yoke when so engaged with the strike andsaid lever when in said forward position constituting toggle linksmovable respectively about the pivotal connection with the strike andabout the axis of the first pin so that the second pin has an overcenteraction with respect to the first pin when the yoke and the lever aremoved rearwardly to vertical cover holding positions, a member carriedby the lever and located closely adjacent the first pin and in fixedrelationship with the axis thereof which member has a vertical aperturetherein, and a vertical screw extending through the. aperture in saidmember and adapted upon rotative adjustment to vary the distance betweenthe axes of the first and second pins which screw has means at the topthereof and closely adjacent the first pin for manually effecting saidrotative adjustment.

2. A catch as set forth in claim 1, wherein said lever is provided withtwo transversely spaced longitudinal flanges having bearing aperturestherein which receive said first pin, and wherein said member carried bythe lever is a structurally separate block which is located be tweensaid flanges of the lever.

3. In a catch for use on a packing case or the like having a main bodyand having a cover upwardly separable from said main body, thecombination of a strike adapted to be fixedly attached to said casecover and having a relatively fixed hook, a base adapted to be fixedlyattached to said case body below said strike, a horizontal transversepivot pin in fixed relationship with the base, a main lever engagingsaid pin and thereby connected with said base for pivotal movement aboutthe axis of said pin, a second horizontal transverse pivot pin carriedby the main lever and spaced from said first pin, a yoke engaging thesecond pin and thereby connected with the lever for pivotal movementabout the axis of said second pin which yoke has a portion pivotallyengageable at its upper end with the hook of the strike when said leveris in a forward position, said yoke, when so engaged with the strike andsaid lever when in said forward position constituting toggle linksmovable respectively about the pivotal connection with the strike andabout the axis of the first pin so that the second pin has an overcenteraction with respect to the first pin when the yoke and the lever aremoved rearwardly to vertical cover holding positions, a first blockcarried by the lever in fixed position thereon 7 and closely adjacentthe first pin which block has a vertical aperture therein, a secondblock carried by the lever and vertically movable with respect thereto,said second block having a transverse aperture therein which receivesand fits the second pin and also having a vertical threaded aperturetherein which is in alignment with the vertical aperture in the firstblock, and a vertical screw extending through the aperture in the firstblock and into the threaded aperture in the second block which screw isheld against vertical movement relative to the first block and whichscrew has means at the top thereof and closely adjacent the first pinfor manually rotating said screw to enable it to vertically move thesecond block and the second pin.

4. A catch as set forth in claim 3, wherein said first block has atransverse aperture therein which receives and fits said first pin, andwherein said vertical aperture in the first block is offset from saidtransverse aperture so that the top of the screw is readily accessible.

5. A catch as set forth in claim 4, wherein said screw has an annulargroove therein positioned to receive and fit said first pin so that saidfirst pin at least assists in preventing vertical movement of saidscrew.

6. A catch as set forth in claim 5, wherein said first block has atransverse retaining pin therein additional to said first pin whichretaining pin is also entered in said annular groove in the screw andcooperates with the first pin for preventing vertical movement of saidscrew.

7. In a catch for use on a packing case or the like having a main bodyand having a cover upwardly separable from said main body, thecombination of a strike adapted to be fixedly attached to said casecover and having a relatively fixed hook, a base adapted to be fixedlyattached to said case body below said strike, a horizontal transversepivot pin in fixed relationship with the base, a main lever havinglongitudinally elongated transverse bearing apertures which receive saidpin for pivotally connecting the lever with said base, a secondhorizontal transverse pivot pin carried by the main lever and spacedfrom said first pin, a yoke engaging the second pin and therebypivotally connected with the lever which yoke has a portion pivotallyengageable at its upper end with the book of the strike when said leveris in a forward position, said yoke when so engaged with the strike andsaid lever when in said forward position constituting toggle linksmovable respectively about the pivotal connection with the strike andabout the axis of the first pin so that the second pin has an overcenteraction with respect to the first pin when the yoke and the lever aremoved rearwardly to vertical cover holding positions, a block carried bythe lever and located closely adjacent the first pin and in fixedrelationship with the axis thereof which block has a vertical aperturetherein, and a vertical screw extending through the aperture in saidmember and adapted upon rotative adjustment to vertically move the leverand the second pin relatively to the fixed first pin which screw hasmeans at the top thereof and closely adjacent the first pin for manuallyeffecting said rotative adjustment.

8. A catch as set forth in claim 7, wherein said block is formedintegrally with said first pin.

9. In a catch for use on a packing case or the like having a main bodyand having a cover upwardly separable from said main body, thecombination of a strike adapted to be fixedly attached to said casecover and having a relatively fixed book, a base adapted to be fixedlyattached to said case body below said strike, a horizontal transversepivot pin in fixed relationship with the base, a main lever engagingsaid pin and thereby connected with said base for pivotal movement aboutthe axis of the pin, a second horizontal transverse pivot pin carried bythe main lever and spaced from said first pin, a yoke engaging thesecond pin and thereby connected with the lever for pivotal movementabout the axis of the second pin which yoke has a portion pivotallyengageable at its upper end with the book of the strike when said leveris in a forward position, said yoke when so engaged with the strike andsaid lever when in said forward position constituting toggle linksmovable respectively about the pivotal connection with the strike andabout the axis of the first pin so that the second pin has an overcenteraction with respect to the first pin when the yoke and the lever aremoved rearwardly to vertical cover holding positions, a member carriedby the lever and located closely adjacent the first pin and in fixedrelationship with the axis thereof which member has a vertical threadedaperture therein, a screw entered in the last said aperture and havingmeans at the top thereof and closely adjacent the first pin for manuallyeffecting rotary adjustment of said screw, a spring carried by the leverand serving to resist relative upward movement of said second pin andsaid yoke when the lever and the yoke are moved to their cover holdingpositions, and means initially spaced from the screw and engageablethereby to limit said relative upward movement, the limiting action ofthe screw being variable in accordance with rotary adjustment thereof10. A catch as set forth in claim 9, wherein said member carried by thelever is a structurally separate block, and wherein a compression springis interposed between said block and said screw engageable means.

References Cited in the file of this patent UNITED STATES PATENTS830,182 Skov Sept. 4, 1906 1,898,742 Phillips Feb. 21, 1933 2,605,123Claud-Mantle July 29, 1952 FOREIGN PATENTS 481,883 Great Britain Mar.18, 1938 676,005 Germany May 24, 1939

